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參數(shù)資料
| 型號： | DS87C550 |
| 廠商： | Maxim Integrated Products, Inc. |
| 英文描述： | EPROM High-Speed Micro with A/D and PWM(帶 A/D 和 PWM的EPROM/ROM高速微控制器) |
| 中文描述： | 存儲器高速微與A / D及PWM（帶A / D轉(zhuǎn)換和脈寬調(diào)制的存儲器/ ROM的高速微控制器） |
| 文件頁數(shù)： | 18/27頁 |
| 文件大?。?/td> | 119K |
| 代理商： | DS87C550 |
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APPLICATION NOTE 78
030998 18/27
ORL EXIF, #08h ;Switch to crystal as clock source.
SETB REN_0 ;Crystal is active, enable receiver.
POP ACC ;Restore Accumulator.
RET ;Device is now running from crystal. Exit.
;***************************************************************************
;RING_ENA – This subroutine checks to see if there is any serial port
; activity, and if not, switches back to the ring oscillator.
;***************************************************************************
RING_ENA: PUSH ACC ;Save accumulator
WAIT_SERIAL:
MOV A, STATUS ;Test lower nibble of status reg for serial
ANL A, #0Fh ; port activity. If serial ports are still
JNZ WAIT_SERIAL ; active, wait before switching to ring.
CLR REN_0 ;Ignore any serial port activity while running
; from ring oscillator.
CLR IE1 ;Clear any outstanding serial interrupts that
SETB EX1 ; may have been generated by serial data and
; reenable external interrupt 1 to detect the
; start of another serial transfer.
ANL EXIF, #0F7h ;Clear XT/RG to enable ring oscillator.
ORL PMR, #08h ;Set XTOFF bit to disable crystal.
POP ACC ;Restore Accumulator.
RET ;Device is now running from ring. Exit.
DEVELOPING A POWER MANAGEMENT
FRAMEWORK
The Dallas Semiconductor approach to power manage-
ment allows system designers to reduce power con-
sumption while maintaining maximum performance. To
achieve the maximum possible savings, the device
operating conditions should be carefully analyzed and a
power management scheme developed.
The determination of which power management modes
to utilize, when to switch modes, and how to handle
high–priority tasks is application dependent. No single
approach will suit all possible combinations. In general,
the selection of clock speeds and sources depends on
the assigned tasks, and the need for timing–dependent
operations such as serial ports activity.
There are two basic classes of systems which employ
power management. The first is systems which hiber-
nate or spend almost all of their operating time in a
standby state, such as Stop or PMM2. These systems
are often used in unattended systems to gather data or
as environmental monitors. They are characterized by
relatively infrequent I/O activity at specific intervals. The
second class of systems usually performs a high rate of
I/O activity on several devices, or otherwise must be
operating constantly. A hibernation approach would be
impractical in this instance as the device would spend
most of its time simply restarting from the low power
state. These two approaches are discussed in more
detail in the following sections.
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS87C550-FCL | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:EPROM High-Speed Micro with A/D and PWM |
| DS87C550-FNL | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:EPROM High-Speed Micro with A/D and PWM |
| DS87C550-KCL | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:EPROM High-Speed Micro with A/D and PWM |
| DS87C550-QCL | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:EPROM High-Speed Micro with A/D and PWM |
| DS87C550-QCL+ | 功能描述:IC MCU EPROM ADC/PWM HS 68-PLCC RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:87C 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:260 系列:73S12xx 核心處理器:80515 芯體尺寸:8-位 速度:24MHz 連通性:I²C，智能卡，UART/USART，USB 外圍設(shè)備:LED，POR，WDT 輸入/輸出數(shù):9 程序存儲器容量:64KB（64K x 8） 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:2K x 8 電壓 - 電源 (Vcc/Vdd):2.7 V ~ 5.5 V 數(shù)據(jù)轉(zhuǎn)換器:- 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:68-VFQFN 裸露焊盤 包裝:管件 |
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